The incidence of perinatal stroke is high, similar to that in the elderly, and produces a significant morbidity and severe long-term neurologic and cognitive deficits, including cerebral palsy, epilepsy, neuropsychological impairments, and behavioral disorders. Emerging clinical data and data from experimental models of cerebral ischemia in neonatal rodents have shown that the pathophysiology of perinatal brain damage is multifactorial. These studies have revealed that, far from just being a smaller version of the adult brain, the neonatal brain is unique with a very particular and age-dependent responsiveness to hypoxia-ischemia and focal arterial stroke. In this review, we discuss fundamental clinical aspects of perinatal stroke as well as some of the most recent and relevant findings regarding the susceptibility of specific brain cell populations to injury, the dynamics and the mechanisms of neuronal cell death in injured neonates, the responses of neonatal blood-brain barrier to stroke in relation to systemic and local inflammation, and the long-term effects of stroke on angiogenesis and neurogenesis. Finally, we address translational strategies currently being considered for neonatal stroke as well as treatments that might effectively enhance repair later after injury.

OBJECTIVES: In infants with hypoxic-ischemic encephalopathy (HIE), conflicting information on the association between early glucose homeostasis and outcome exists. We characterized glycemic profiles in the first 12 hours after birth and their association with death and neurodevelopmental impairment (NDI) in neonates with moderate or severe HIE undergoing therapeutic hypothermia. METHODS: This post hoc analysis of the High-dose Erythropoietin for Asphyxia and Encephalopathy trial included n = 491 neonates who had blood glucose (BG) values recorded within 12 hours of birth. Newborns were categorized based on their most extreme BG value. BG >200 mg/dL was defined as hyperglycemia, BG <50 mg/dL as hypoglycemia, and 50 to 200 mg/dL as euglycemia. Primary outcome was defined as death or any NDI at 22 to 36 months. We calculated odds ratios for death or NDI adjusted for factors influencing glycemic state (aOR). RESULTS: Euglycemia was more common in neonates with moderate compared with severe HIE (63.6% vs 36.6%; P < .001). Although hypoglycemia occurred at similar rates in severe and moderate HIE (21.4% vs 19.5%; P = .67), hyperglycemia was more common in severe HIE (42.3% vs 16.9%; P < .001). Compared with euglycemic neonates, both, hypo- and hyperglycemic neonates had an increased aOR (95% confidence interval) for death or NDI (2.62; 1.47-4.67 and 1.77; 1.03-3.03) compared to those with euglycemia. Hypoglycemic neonates had an increased aOR for both death (2.85; 1.09-7.43) and NDI (2.50; 1.09-7.43), whereas hyperglycemic neonates had increased aOR of 2.52 (1.10-5.77) for death, but not NDI. CONCLUSIONS: Glycemic profile differs between neonates with moderate and severe HIE, and initial glycemic state is associated death or NDI at 22 to 36 months.

OBJECTIVE: To study the association between the Sarnat exam (SE) performed before and after therapeutic hypothermia (TH) and outcomes at 2 years in infants with moderate or severe hypoxic-ischaemic encephalopathy (HIE). DESIGN: Secondary analysis of the High-dose Erythropoietin for Asphyxia and EncephaLopathy Trial. Adjusted ORs (aORs) for death or neurodevelopmental impairment (NDI) based on SE severity category and change in category were constructed, adjusting for sedation at time of exam. Absolute SE Score and its change were compared for association with risk for death or NDI using locally estimated scatterplot smoothing curves. SETTING: Randomised, double-blinded, placebo-controlled multicentre trial including 17 centres across the USA. PATIENTS: 479/500 enrolled neonates who had both a qualifying SE (qSE) before TH and a SE after rewarming (rSE). INTERVENTIONS: Standardised SE was used across sites before and after TH. All providers underwent standardised SE training. MAIN OUTCOME MEASURES: Primary outcome was defined as the composite outcome of death or any NDI at 22-36 months. RESULTS: Both qSE and rSE were associated with the primary outcome. Notably, an aOR for primary outcome of 6.2 (95% CI 3.1 to 12.6) and 50.3 (95% CI 13.3 to 190) was seen in those with moderate and severe encephalopathy on rSE, respectively. Persistent or worsened severity on rSE was associated with higher odds for primary outcome compared with those who improved, even when qSE was severe. CONCLUSION: Both rSE and change between qSE and rSE were strongly associated with the odds of death/NDI at 22-36 months in infants with moderate or severe HIE.

BACKGROUND: An ancillary study of the High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) trial for neonates with hypoxic-ischemic encephalopathy (HIE) and treated with therapeutic hypothermia examined the hypothesis that neonates randomized to receive erythropoietin (Epo) would have a lower seizure risk and burden compared with neonates who received placebo. METHODS: Electroencephalograms (EEGs) from 7/17 HEAL trial centers were reviewed. Seizure presence was compared across treatment groups using a logistic regression model adjusting for treatment, HIE severity, center, and seizure burden prior to the first dose. Among neonates with seizures, differences across treatment groups in median maximal hourly seizure burden were assessed using adjusted quantile regression models. RESULTS: Forty-six of 150 (31%) neonates had EEG seizures (31% in Epo vs 30% in placebo, p = 0.96). Maximal hourly seizure burden after the study drug was not significantly different between groups (median 11.4 for Epo, IQR: 5.6, 18.1 vs median 9.7, IQR: 4.9, 21.0 min/h for placebo). CONCLUSION: In neonates with HIE treated with hypothermia who were randomized to Epo or placebo, we found no meaningful between-group difference in seizure risk or burden. These findings are consistent with overall trial results, which do not support Epo use for neonates with HIE undergoing therapeutic hypothermia. IMPACT: In the HEAL trial of erythropoietin (Epo) vs placebo for neonates with encephalopathy presumed due to hypoxic-ischemic encephalopathy (HIE) who were also treated with therapeutic hypothermia, electrographic seizures were detected in 31%, which is lower than most prior studies. Epo did not reduce the proportion of neonates with acute provoked seizures (31% in Epo vs 30% in placebo) or maximal hourly seizure burden after the study drug (median 11.4, IQR 5.6, 18.1 for Epo vs median 9.7, IQR 4.9, 21.0 min/h for placebo). There was no anti- or pro-convulsant effect of Epo when combined with therapeutic hypothermia for HIE.